Double-acting steam-air hammer, in particular for pile immersion



y 25, 1967 G. J. KLEBANOV 3,332,503

DOUBLE-ACTING STEAMAIR HAMMER, IN PARTICULAR FOR FILE IMMERSION Filed March 12, 1964 2 Sheets-Sheet 1 July 25, 1967 (5 J. KLE Nov DOUBLE-ACTENG STEA IR HAMMER, IN PARTICULAR FOR PILE IMMERSI'ON 2 She ets-Sheet 2 Filed March 12. 1964 United States Patent 3,332,503 DOUBLE-ACTING STEAM-AIR HAMNIER, IN PARTICULAR FOR PILE IMMERSION Girsh Jakovlevich Klebanov, Moscow, U.S.S.R., assignor to Vsesouzny Nauchno-Issledovatelsky Institute Stroitelnogo i Dorozhnogo Maschinostroenia, Moscow,

U.S.S.R.

Filed Mar. 12, 1964, Ser. No. 352,428 6 Claims. (Cl. 173-134) This invention relates to double-acting steam or air operated hammers and, in particular, to hammers used for pile driving.

Generally, the present suspension double-acting steamair hammer comprises a cylinder having working and idling chambers, a differential percussive piston located within the cylinder for distributing a working medium delivered into the working and idling chambers, a differential percussive piston located within the cylinder for distributing a working medium delivered into the working and idling chambers, conduit means providing communication between the working and idling chambers, an adjustable non-return valve means operative for by-passing a part of the Working medium from the working chamber to the idling chamber during the working stroke of the piston for permitting expansion of the remaining part of the working medium in dependence upon the adjustment of the valve means in accordance with the required power of a single impact, a travelling anvil operably related to the percussive piston, and a flow regulating slide valve arranged in the path of the working medium delivered to the hammer.

The known steam or air operated double-acting hammers either provided with slide valves or valveless are characterized in that the movement of the percussive piston or piston-ram is the result of the action of the kinetic energy of steam or air which under certain pressure is continuously delivered from a suitable source such as a compressor or steam boiler into the working or idle chambers of the cylinder which are separated by means of rings on the percussive piston or piston-ram.

The main drawback of such hammers is their low efficiency because air or steam must be admitted continuously into the cylinder chambers along the whole length of stroke of the percussive piston both during its working movement and its idle movement. The internalenergy of the steam or air developing at expansion is not used in such hammers, and this accounts for their low efiiciency. More specifically, the underlying reason resides in the necessity of lifting the percussive piston during the idle movement along the whole length of such movement under the pressure of the steam or air which enters the cylinder chamber.

The percussive piston can perform the full length of the idle movement only on the condition that forces at the end of the movement acting on piston in downward and upward direction become equal. This is ensured only when the motivating medium is admitted along the whole length of the movement irrespective of the ratio of the piston working areas above and below the piston. Noncompliance with this condition, i.e. the admission of the Working or motivating medium along the whole length of the movement, can lead to the suspension of the percussive piston. In other words, the piston will stop its movement.

Another drawback of theknown hammers is the presence of a clearance space or dead space which is required for the compensation of resulting air cushions, which in turn causes an increase in the consumption of the working medium.

Furthermore, in order to cope with the reactive forces developed during the operation of such hammers, and to 'ice prevent the lifting of the hammer, namely, its disconnection from the pile, it is necessary to increase considerably the weight thereof.

The object of the present invention is to provide a hammer assemblage which eliminates the above-mention ed drawbacks and affords a steam or air hammer of low weight and which consumes small amount of steam or compressed air during the operation thereof.

In the hammer of the present invention, the internal energy of the steam or air developing at the expansion thereof is employed and the same is eliected by connecting the idle and working piston chambers by means of piping provided with adjustable valve means which delivers the surplus of the working or motivating medium from the working chamber into the idle chamber. Due to this arrangement it is not necessary to admit the working medium along the whole length of the movement thus reducing considerably the consumption of the working medium and decreasing to a minimum the dead space.

Furthermore, a damper means operative for coupling with the reactive forces developing during the operation of the hammer is mounted on the cylinder cover or closure in order to decrease considerably the weight of hammer, and hence the amount of metal used for the manufacture thereof.

Thus, the present hammer fulfills the requirements of modern technique and is the most efficient among the hammers of this class. Moreover, due to the considerable decrease in the weight of the hammer, its operation is facilitated and the manufacturing costs substantially reduced.

Additional objects and advantages of the invention will become more readily apparent to persons skilled in the art from the ensuing detailed description and drawings, and in which drawings:

FIGURE 1 is a view in longitudinal cross-section of an embodiment of the invention, and

FIGURE 2 is a view taken along the line B-B of FIGURE 1, the view looking in the direction of the arrows and being on a larger scale.

The hammer comprises a cylinder body 1 having an idling chamber 2 and a working chamber 3. A stepped percussive piston 4 is located in the cylinder. Communication between the chambers 2 and 3 is prevented by piston rings 5 and 6 provided on the piston 4 and of the working medium, such as compressed air is directed through a pipe or conduit 19 equipped with a flow regulating slide valve 7 to chamber 3 thus preparing the hammer for operation. Air is exhausted from the hammer via exhaust ports 18. A by-pass valve 8 which is self-setting in accordance with the hammer load is mounted in a pipeline 9 connecting the chambers 2 and 3. The hammer body, by means of a spring 10 rests on a travelling anvil 11 which in turn, rests on the pile cap. The chamber 3 is closed by a cover 12 to which a steam-air damper is made fast.

The damper comprises a cylinder 13, piston 14 and piston rings 15. The chamber 3 communicates with the working space of the cylinder 13 by pipe line 16 connecting ports 16' with inlet ports 16a. The by-pass valve 8 is a usual hydraulic spring valve or any other adjustable spring valve which can ensure the return of surplus quantity of steam or air from the working chamber into the idling chamber. The cylinder 13 of the damper may be provided with means 23 for securing the hammer in the pile driver g-uideways.

For admission of the working medium into the working chamber, the cylinder body is provided with the inlet channels 17, and as above stated the medium is exhausted through the ports 18 to the atmosphere.

The hammer operates as follows: steam or air from a boiler or compressor passes through the pipe 19, slide Patented July 25, 1967 valve 7, pipe line 22, ring chamber 20 and from the latter via ports 21 enters the idling chamber 2. Under the pressure of working medium, the percussive piston 4 moves to the right where at this time the compression operation takes place. Prior to reaching the extreme or right position, the piston opens ports 17 of the inlet channels 17 through which the working medium enters the working chamber 3 and upon completion of its function is exhausted through the ports 18. More specifically, it will be noted that at the instant the part of the piston 4 of larger diameter passes the ports 17' of the channels 17 a flow path is provided to the working chamber.

The piston area and, accordingly, the area of the cylinder cross-section at the right end are substantially greater than at the left end. Hence, for equalization of forces directed to the left and to the right, the different pressures are required and these pressures are received immediately after the working medium enters the cylinder chambers. In this case, the piston 4 prior to making a :full stroke should return back but the by-pass valve 8 prevents such return. The compressed working medium which is in a clearance space and a portion of the new working medium enter the working chamber are bypassed through the valve 8 back into the chamber 2 in order to participate in the subsequent cycles. Thus, the admission of the working medium into Working chamber 3 of the cylinder is eifected for the short period the port 17' is uncovered by the piston 4. However, during a certain part of the stroke the working medium, depending on the load (required energy of percussion) can be by-passed into the chamber 3 without creating the indicated power and simultaneously, the admission of the working medium is arrested.

During the rest of the stroke after the opening of the by-pass valve, the expansion of the working medium is effected and the length of this part of the stroke is determined by the valve spring tension (adjusting). In correspondence with the variation of the inlet length of the stroke also varies the indicated power of cycle and the percussive energy of the hammer.

As it is known, at the beginning of the pile driving, due to the small resistance of ground, the pile driving per one hammer stroke is considerably less than that at the end of the operation. In order to exclude the distortion of the piles at the beginning of the operation, the slow driving of the piles down to a depth of 1.5-2.0 m. depth and, hence, correspondingly smaller energy of hammer blows are required. In this case, every subsequent hammer blow should differ from the foregoing blow by value corresponding to the required depth of driving.

The function of regulating the blow energy in the proposed hammer in accordance with the required depth of driving is performed by the flow regulating slide valve 7 which is operably connected by any mechanical means with the anvil following the driven pile or percussive tool. By means of the design, at too great driving of the pile due to a hammer blow, the flow regulating slide valve 7 moves to the left, thus decreasing the admission of the working medium and, consequently, the energy for the subsequent blow and vice versa. With the increasing of resistance, the flow regulating slide valve to the right increasing the admission of the working medium and, correspondingly, the energy for performing the following blow. Thus, the flow regulating slide valve 7 is a selfacting device adjusting the energy of the hammer blow in accordance with the required load (resistance). The pile driving per one blow is measured by the relative movement of the anvil 11 and the hammer. Due to the continuous admission of the working medium through pipe lines 16 into the working space of the cylinder 13, the damper body in accordance with the increase of reactive forces in the working chamber 3 moves to the right. Hence, the piston 14 moves to the right thereby closing ports 16a developing in the cylinder 13 the pressure capable of absorbing completely the reactive forces and causing the lifting of the hammer from the pile.

While the drawings illustrate the invention in the horizontal position, the hammer can operate successfully in the vertical position as well.

This invention is not to be confined to any strict conformity to the showings in the drawing but changes or modifications may be made therein so long as such changes or modifications mark no material departure from the spirit and scope of the appended claims.

What is claimed is:

1. A suspension double-acting steam-air hammer, comprising a cylinder having working and idling chambers, a differential percussive piston located within said cylinder for distributing a working medium delivered into the working and idling chambers, conduit means providing communication between said working and idling chambers, an adjustable non-return valve means operative for by-passing a part of the working medium from the working chamber to the idling chamber during the working stroke of the piston for permitting expansion of the remaining part of the working medium in dependence upon the adjustment of said valve means in accordance with the required power of a single impact, a travelling anvil operably related to said percussive piston, and a flow regulating slide valve arranged in the path of the working medium delivered to the hammer.

2. The suspension double-acting steam-air hammer as claimed in claim 1 including means actuated by said travelling anvil for controlling the opening of the flow regulating slide valve in dependence upon the amount of anvil t-ravel per one impact.

3. The suspension double-acting steam-air hammer as claimed in claim 1 including a pneumatic cylinder-piston damper operably related to the cylinder for damping the reactive force acting on the hammer during operation.

4. The suspension double-acting steam-air hammer as claimed in claim 1 including means actuated by said travelling anvil for controlling the opening of the flow regulating slide valve in dependence upon the amount of anvil travel per one impact, and a pneumatic cylinderpiston damper operably related to the cylinder for damping the reactive force acting on the hammer during operation.

5. The suspension double-acting steam-air hammer as claimed in claim 1 including a pneumatic cylinder-piston damper for damping the reactive force acting on the hammer during operation, and conduit means connecting the working chamber of the hammer cylinder with the working space of the damper cylinder for delivering working medium to the damper for maintaining a constant ratio between the value of the hammer reactive force and the damper active force under various hammer operating conditions.

6. The suspension double-acting steam-air hammer as claimed in claim 5 including means actuated by said travelling anvil for controlling the opening of the flow regulating slide valve in dependence upon the amount of anvil travel per one impact.

References Cited UNITED STATES PATENTS 1,065,339 6/1913 Brazelle 173-134 1,871,601 8/1932 Gaty l73134 2,090,842 8/1937 Kiecksee 173-162 2,789,540 4/1957 Kupka et al. l73l34 2,904,964 9/1959 Kupka 173134 3,049,097 8/1962 Kershaw l73-134 3,200,893 8/1965 Leavell 173- 162 FRED C. MATTERN, JR., Primary Examiner.

L. P. KESSLER, Assistant Examiner. 

1. A SUSPENSION DOUBLE-ACTING STREAM-AIR HAMMER, COMPRISING A CYLINDER HAVING WORKING AND IDLING CHAMBERS, A DIFFERENTIAL PERCUSSIVE PISTON LOCATED WITHIN SAID CYLINDER FOR DISTRIBUTING A WORKING MEDIUM DELIVERED INTO THE WORKING AND IDLING CHAMBERS, CONDUIT MEANS PROVIDING COMMUNICATION BETWEEN SAID WORKING AND IDLING CHAMBERS, AN ADJUSTABLE NON-RETURN VALVE MEANS OPERATIVE FOR BY-PASSING A PART OF THE WORKING MEDIUM FROM THE WORKING CHAMBER TO THE IDLING CHAMBER DURING THE WORKING STROKE OF THE PISTON FOR PERMITTING EXPANSION OF THE REMAINING PART OF THE WORKING MEDIUM IN DEPENDENCE UPON THE ADJUSTMENT OF SAID VALVE MEANS IN ACCORDANCE WITH THE REQUIRED POWER OF A SINGLE IMPACT, A TRAVELLING ANVIL OPERABLY RELATED TO SAID PERCUSSIVE PISTON, AND A FLOW REGULATING SLIDE VALVE ARRANGED IN THE PATH OF THE WORKING MEDIUM DELIVERED TO THE HAMMER. 